Light-emitting device

ABSTRACT

A light-emitting device includes a light-emitting structure with a side surface, and a reflective layer covering the side surface. The light-emitting structure has a first light-emitting angle and a second light-emitting angle. The difference between the first light-emitting angle and the second light-emitting angle is larger than 15°.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a non-provisional patent application,claiming the benefit of priority of TW Patent Application No. 104144679filed on Dec. 31, 2015 and TW Patent Application No. 105126557 filed onAug. 19, 2016.

TECHNICAL FIELD

The present disclosure relates to a light-emitting device and inparticular to a light-emitting device comprising a reflective layercovering two sides of a light-transmitting body.

DESCRIPTION OF THE RELATED ART

The light-emitting diodes (LEDs) have the characteristics of low powerconsumption, long operational life, small volume, quick response andstable opto-electrical property of emitted light. Recently, thelight-emitting diodes gradually are used in a backlight module of aliquid crystal display.

SUMMARY OF THE DISCLOSURE

A light-emitting device includes a light-emitting structure with a sidesurface, and a reflective layer covering the side surface. Thelight-emitting structure has a first light-emitting angle and a secondlight-emitting angle. The difference between the first light-emittingangle and the second light-emitting angle is larger than 15°.

The following description illustrates embodiments and together withdrawings to provide a further understanding of the disclosure describedabove.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a bottom view of a light-emitting device in accordancewith an embodiment of the present disclosure.

FIG. 1B shows a cross-sectional view taken along lines I-I of FIG. 1A.

FIG. 1C shows a cross-sectional view taken along lines II-II of FIG. 1A.

FIG. 1D shows an enlarged view of a circled area A in FIG. 1B.

FIG. 1E shows an enlarged view of a circled area B in FIG. 1C.

FIG. 1F shows drawings of how to measure a light-emitting device.

FIGS. 2A˜2D show cross-sectional views of light-emitting devices inaccordance with embodiments of the present disclosure.

FIGS. 3A˜3G show cross-sectional views of making a light-emitting devicein accordance with an embodiment of the present disclosure.

FIGS. 4A˜4G show top views of FIGS. 3A˜3G respectively.

FIGS. 5A˜5C show cross-sectional views of light-emitting devices inaccordance with embodiments of the present disclosure.

FIGS. 6A˜6B show cross-sectional views of forming a second reflectivelayer in accordance with an embodiment of the present disclosure.

FIGS. 7A˜7G show cross-sectional views of making a light-emitting devicein accordance with an embodiment of the present disclosure.

FIGS. 8A˜8C show cross-sectional views of light-emitting devices inaccordance with embodiments of the present disclosure respectively.

FIGS. 9A˜9E show top views of making a light-emitting device inaccordance with an embodiment of the present disclosure.

FIGS. 10A˜10D show cross-sectional views of light-emitting devices inaccordance with embodiments of the present disclosure respectively.

FIG. 11A shows a cross-sectional view of one step of making alight-emitting device in accordance with an embodiment of the presentdisclosure.

FIG. 11B shows a top view of one step of making a light-emitting devicein accordance with an embodiment of the present disclosure.

FIG. 11C shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 12A shows a top view of a light-emitting device in accordance withan embodiment of the present disclosure.

FIG. 12B shows a cross-sectional view taken along lines I-I of FIG. 12A.

FIGS. 13A˜13F show cross-sectional views of making a light-emittingdevice in accordance with an embodiment of the present disclosure.

FIGS. 14A˜14F show top views of FIGS. 13A˜13F respectively.

FIGS. 15A˜15F show cross-sectional views of making a light-emittingdevice in accordance with an embodiment of the present disclosure.

FIGS. 16A˜16F show top views of FIGS. 15A˜15F respectively.

FIGS. 17A˜17F show cross-sectional views of making a light-transmittingbody having a top surface with a wavy shape in accordance with anembodiment of the present disclosure.

FIGS. 18A˜18E show cross-sectional views of a light-transmitting bodyhaving a top surface with different structures.

FIG. 19 shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIGS. 19A˜19C show cross-sectional views of light-emitting devices usedin the simulation.

FIGS. 20A˜20G show cross-sectional views of making a light-emittingdevice in accordance with an embodiment of the present disclosure.

FIGS. 21A˜21G show top views of FIGS. 20A˜20G, respectively.

FIG. 22A shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 22B shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIG. 22C shows a cross-sectional view of a light-emitting device inaccordance with an embodiment of the present disclosure.

FIGS. 23A˜23F show cross-sectional views of making a light-emittingdevice in accordance with an embodiment of the present disclosure.

FIGS. 24A˜24F show top views of FIGS. 23A˜23F respectively.

FIGS. 25A˜25D show perspective views of making a light-emitting devicein accordance with an embodiment of the present disclosure.

FIGS. 26A˜26C show cross-sectional views of FIGS. 25B˜25D respectively.

FIG. 27A shows a cross-sectional view of an edge-lit backlight unit of aliquid crystal display in accordance with an embodiment of the presentdisclosure.

FIG. 27B shows a perspective view of a light source and a light-guidingplate.

FIG. 28 shows a cross-sectional view of an edge-lit backlight unit of aliquid crystal display in accordance with an embodiment of the presentdisclosure.

FIG. 29 shows a cross-sectional view of an edge-lit backlight unit of aliquid crystal display in accordance with an embodiment of the presentdisclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The drawings illustrate the embodiments of the application and, togetherwith the description, serve to illustrate the principles of theapplication. The same name or the same reference number given orappeared in different paragraphs or figures along the specificationshould has the same or equivalent meanings while it is once definedanywhere of the disclosure. The thickness or the shape of an element inthe specification can be expanded or narrowed. It is noted that theelements not drawn or described in the figure can be included in thepresent application by the skilled person in the art.

FIG. 1A shows a bottom view of a light-emitting device 100 in accordancewith an embodiment of the present disclosure. For clear illustration,FIG. 1A only shows some layers and each layer is drawn in solid line (aconductive layer 1116 is drawn in dot line and will be described later)regardless of its material being non-transparent, transparent, orsemi-transparent. FIG. 1B shows a cross-sectional view taken along linesI-I of FIG. 1A. FIG. 1C shows a cross-sectional view taken along linesII-II of FIG. 1A. FIG. 1D shows an enlarged view of a circled area A inFIG. 1B. FIG. 1E shows an enlarged view of a circled area B in FIG. 1C.For simplified illustration, a light-emitting structure 11 is shown ascuboid in FIGS. 1B and 1C and the detailed structure will be describedin FIGS. 1D and 1E.

Referring to FIGS. 1A, 1B, and 1D, the light-emitting device 100includes a light-emitting structure 11, a light-transmitting body 12, awavelength-conversion body 13, a first reflective layer 14, extensionelectrode layers 15A, 15B, and a second reflective layer 17. Thelight-emitting structure 11 includes a patterned substrate 110 and twolight-emitting bodies 111A, 111B. The patterned substrate 110 issubstantially a cuboid and includes a top surface 1101, a bottom surface1102 opposite to the top surface 1101, and four side surfaces (a firstside surface 1103, a second side surface 1104, a third side surface1105, and a fourth side surface 1106) connecting between the top surface1101 and the bottom surface 1102. The bottom surface 1102 is a patternedsurface with a concave-convex structure in a regular or irregulararrangement. The light-transmitting body 12 covers the top surface 1101,the four side surface 1103˜1106 and a portion of the bottom surface1102.

Referring to FIG. 1D, in this embodiment, the light-emitting structure11 includes the patterned substrate 110, the two light-emitting bodies111A, 111B commonly formed on the patterned substrate 110, a trench 112formed between the two light-emitting bodies 111A, 111B such that thetwo light-emitting bodies 111A, 111B are physically separated from eachother. Each light-emitting body 111A, 111B includes a first-typesemiconductor layer 1111, an active layer 1112, and a second-typesemiconductor layer 1113. A first insulation layer 1114 is formed in thetrench 112 and covers the first-type semiconductor layers 1111 of thelight-emitting bodies 111A, 111B to avoid undesired electrical path(short circuit). A second insulation layer 1115 is formed on the firstinsulation layer 1114 to expose the second-type semiconductor layers1113 of the light-emitting bodies 111A, 111B. A conductive layer 1116 isformed on the second insulation layer 1115 to expose the second-typesemiconductor layers 1113 of the light-emitting bodies 111A, 111B. Inaddition, the second insulation layer 1115 covers a sidewall of thefirst insulation layer 1114. The conductive layer 1116 covers a portionof a sidewall of the second insulation layer 1115 and extends to thesecond-type semiconductor layer 1113. A third insulation layer 1117 isformed on the conductive layer 1116, covers the light-emitting bodies111A, 111B and exposes a portion of the conductive layer 1116. A firstelectrode layer 1118 and a second electrode layer 1119 are electricallyconnected to the light-emitting bodies 111A, 111B, respectively. Theelectrical connection between the light-emitting bodies 111A, 111B isdescribed later. An ohmic contact layer 1120 is optionally formedbetween the second-type semiconductor layer 1113 and the conductivelayer 1116 for lowering a driving voltage of the light-emitting device100.

For clear illustration, the conductive layer 1116 of FIG. 1A is drawn ina dot line. Referring to FIGS. 1A, 1D, and 1E, the conductive layer 1116has a first region 1161, a second region 1161 (the hatch area in FIG.1A) and a third region 1163. The first region 1161 is formed merely onthe light-emitting body 111A and physically separated from the secondregion 1162. The second region 1162 surrounds the first region 1161. Thesecond region 1162 contacts the first-type semiconductor layer 1111 ofthe light-emitting body 111A, and is further formed on the secondinsulation layer 1115 in the trench 112 to extend to the second-typesemiconductor layer 1113 of the light-emitting body 111B so theconductive layer 1116 serially connects the light-emitting body 111Awith the light-emitting body 111B (due to the position of I-I line, theelectrical connection is not shown in FIG. 1D).

Referring to FIGS. 1A, 1D and 1E, a plurality of holes 1110 is formed inthe third insulation layer 1110, and the holes 1110 are formed merely onthe light-emitting body 111A and not formed on the light-emitting body111B. The first electrode layer 1118 extends into the holes 1110 andelectrically connected to the first region 1161 of the conductive layer1116 on the light-emitting body 111A so the first electrode layer 1118is electrically connected to the second-type semiconductor layer 1113 ofthe light-emitting body 111A. The third region 1163 of the conductivelayer 1116 is formed merely on the light-emitting body 111B. The secondelectrode layer 1119 contacts directly the third region 1163 of theconductive layer 1116 exposed from the third insulation layer 1117. Thethird region 1163 of the conductive layer 1116 contacts the first-typesemiconductor layer 1111 of the light-emitting body 111B. In thisembodiment, for example, when the first electrode layer 1118 iselectrically connected to a positive terminal of an external electrodeand the second electrode layer 1119 is electrically connected to anegative terminal of the external electrode, a current flows through thefirst electrode layer 1118 in the holes, the first region 1161 of theconductive layer 1116, the second-type semiconductor layer 1113 of thelight-emitting body 111A, the active layer 1112 of the light-emittingbody 111A, the first-type semiconductor layer 1111 of the light-emittingbody 111A, the second region 1162 of the conductive layer 1116, thesecond-type semiconductor layer 1113 of the light-emitting body 111B,the active layer 1112 of the light-emitting body 111B, the first-typesemiconductor layer 1111 of the light-emitting body 111B, the thirdregion 1163 of the conductive layer 1116 and to the second electrodelayer 1119, so the light-emitting bodies 111A, 111B are electricallyconnected with each other in series. Moreover, based on the aforesaidstructure, a process of forming holes 1110 on the light-emitting body111B can be eliminated and the conductive layer 1116 covers thesidewalls of the light-emitting bodies 111A, 111B for enhancing theluminous flux (lumen) of the light-emitting device 100 and reducing theforward voltage of the light-emitting device 100.

In this embodiment, the first electrode layer 1118, the second electrodelayer 1119 and the conductive layer 1116 can be made of metal, forexample Au, Ag, Cu, Cr, Al, Pt, Ni, Ti, Sn or alloy thereof. The firstinsulation layer 1114 can be a single layer or a multilayer. When thefirst insulation layer 1114 is a single layer, it can comprise oxide,nitride, or polymer. The oxide can comprise Al₂O₃, SiO₂, TiO₂, Ta₂O₅,AlO_(x). The nitride can comprise AlN or SiN_(x). The polymer cancomprise polyimide or BCB. When the first insulation layer 1114 is amultilayer, it can be a stack structure for forming a Distributed BraggReflector whose material comprising Al₂O₃, SiO₂, TiO₂, Ta₂O₅, orSiN_(x). The second insulation layer 1115 and the third insulation layer1117 comprise a material referred to the material of the firstinsulation layer 1114.

Referring to FIGS. 1A and 1C, the light-transmitting body 12 enclosesthe light-emitting structure 11 and is substantially a cuboid.Accordingly, the light-transmitting body 12 is a rectangular in FIG. 1A.The light-transmitting body 12 has a top surface 121, a bottom surface122 opposite to the top surface 121, and four side surfaces (a firstside surface 123, a second side surface 124, a third side surface 15 anda fourth side surface 126) connecting between the top surface 121 andthe bottom surface 122. In FIG. 1A, the first side surface 123 issubstantially parallel to the third side surface 125, and they are thelonger sides of the rectangle. The second side surface 124 and thefourth side surface 126 are parallel to each other and they are theshorter sides of the rectangle. The second reflective layer 17 coversthe first side surface 123 and the third side surface 125 withoutcovering the second side surface 124, the fourth side surface 126, thetop surface 121 and the bottom surface 122 so the second reflectivelayer 17 covers the first side surface 1103 and the third side surface1105 of the light-emitting structure 11.

Referring to FIG. 1C, the second reflective layer 17 has an outersurface 171 and an inner surface 172. The outer surface 171 issubstantially perpendicular to top surface 121 and the inner surface 172has a curved shape. Specifically, a distance (D1) between the innersurface 172 and the outer surface 171 is gradually decreased in adirection from the top surface 121 to the bottom surface 122 of thelight-transmitting body 12. Moreover, the inner surface 172 extends tothe first reflective layer 14 and without connecting to the outersurface 171. In addition, the extension electrode layer 15A overlaps thesecond reflective layer 17 in a Z direction.

Light emitted from the light-emitting structure 11 is reflected by thesecond reflective layer 17 toward the top surface 121 and/or sidesurfaces 124, 126 to exit the light-emitting device 100. Furthermore,the second reflective layer 17 is a mixture including a matrix and aplurality of reflective particles dispersed in the matrix so reflectionof the light emitted from the light-emitted structure 11 occurs withinthe second reflective layer 17 and the reflection is called diffusereflection. The matrix is an insulation material and includessilicone-based material or epoxy-based material. The reflective particleincludes TiO₂, SiO₂, BaSO₄, or Al₂O₃. Since the thickness of the secondreflective layer 17 correlates with its reflectivity which varies withwavelength, the thickness of the second reflective layer 17 (the maximumdistance between the inner surface 172 and the outer surface 171) rangesfrom 50 μm˜160 μm. When the thickness of the second reflective layer 17is less than 50 μm, the second reflective layer 17 has a reflectivity ofless than 90% at 430 nm˜450 nm, has a reflectivity of less than 88% at540 nm˜570 nm, and has a reflectivity of less than 80% at 620 nm˜670 nm.When the thickness of the second reflective layer 17 is about 160 μm,the second reflective layer 17 has a reflectivity of greater than 95% at430 nm˜450 nm, at 540 nm˜570 nm, and at 620 nm˜670 nm. However, thethickness of the second reflective layer 17 is greater than 160 μm,which results in an increase in the thickness of the light-emittingdevice 100 and the cost for making thereof for limiting theapplicability, for example, mobile phone, liquid crystal display,wearable apparatus like watch, wristband, ring, and so on. In anotherembodiment, based on various applications, the second reflective layer17 has a thickness greater than 160 μm, or in a range of 50 μm˜1000 μm.

Referring to FIGS. 1B and 1D, the first reflective layer 14 is formed onthe third insulation layer 1117, and has a first part 141, a secondpart, 142 and a third part 143. The extension electrode layers 15A, 15Bare formed on the first reflective layer 14. Specifically, the firstpart 141 of the first reflective layer 14 covers merely a portion ofsecond part 142 of the first reflective layer 14 is formed between thefirst electrode layer 1118 and the second electrode layer 1119 andcovers a portion of the first electrode layer 1118 and a portion of thesecond electrode layer 1119. The extension electrode layer 15A coversmerely the first part 141 and the second part 142 of the firstreflective layer 14, and the extension electrode layer 15B covers merelythe second part 142 and the third part 143 of the first reflective layer14. The extension electrode layers 15A, 15B contact and are electricallyconnected to the first electrode layer 1118 and the second electrodelayer 1119 respectively. The extension electrode layer 15A has a firstend 151 with a surface coplanar with the second side surface 124, and asecond end 152 formed on the second part 142 of the first reflectivelayer 14 and having a curved cross-section. The extension electrodelayer 15B has a structure similar to that of the extension electrodelayer 15A.

In FIG. 1D, the second part 142 contacted directly the third insulation1117 and fully filled between the first electrode layer 1118 and thesecond electrode layer 1119 and the light-transmitting body 12 is notformed between the first reflective layer 14 and the third insulationlayer 1117. In another embodiment, during manufacturing, thelight-transmitting body 12 can be formed between the first reflectivelayer 14 and the third insulation layer 1117.

Referring to FIGS. 1B and 1C, the wavelength-conversion body 13 isformed within the light-transmitting body 12. In this embodiment, thewavelength-conversion body 13 includes a plurality ofwavelength-conversion particles 131 dispersed in a matrix. Thewavelength-conversion particles 131 covers the top surface 1102, thefirst side surface 1103, the second side surface 111, a portion of thethird side surface 1105 and a portion of the fourth side surface 1106. Aportion of the third side surface 1105 and a portion of the fourth sidesurface 1106 are not covered by the wavelength-conversion particles 131.Alternatively, the wavelength-conversion body 13 and/or thelight-transmitting body 12 further include diffusion powder. The matrixincludes epoxy, silicone, PI, BCB, PFCB, Acrylic resin, PMMA, PET, PC orpolyetherimide. The light-transmitting body 12 includes epoxy, silicone,PI, BCB, PFCB, Acrylic resin, PMMA, PET, PC or polyetherimide. When thematrix of the wavelength-conversion body 13 has a material same as thelight-transmitting body 12, an interface therebetween observed by scanelectron microscope (SEM) is vague and unclear. Or, there is nointerface existing between the wavelength-conversion body 13 and thelight-transmitting body 12, that is, the wavelength-conversion particlesdispersed in the light-transmitting body 12.

The wavelength-conversion particles 131 have a particle size of 5 μm˜100μm and include one or more kinds of inorganic phosphor, organicfluorescent colorants, semiconductors, or combinations thereof. Theinorganic phosphor includes but is not limited to, yellow-greenishphosphor or red phosphor. The yellow-greenish phosphor comprisesaluminum oxide (such as YAG or TAG), silicate, vanadate, alkaline-earthmetal selenide, or metal nitride. The red phosphor includes fluoride(K₂TiF₆:Mn⁴⁺, K₂SiF₆:Mn⁴⁺), silicate, vanadate, alkaline-earth metalsulfide (CaS), metal nitride oxide, a mixture of tungstate andmolybdate. The weight percentage (w/w) of the wavelength-conversionparticles within the matrix is between 50%˜70%. The semiconductorsinclude crystal with nano-sizes, for example, quantum dot. The quantumdot can be ZnS, ZnSe, ZnTe, ZnO, CdS, CdSe, CdTe, GaN, GaP, GaSe, GaSb,GaAs, MN, AlP, AlAs, InP, InAs, Te, PbS, InSb, PbTe, PbSe, SbTe,ZnCdSeS, CuInS, CsPbCl₃, CsPbBr₃, or CsPbI₃.

The diffusing powder includes titanium dioxide, silicon dioxide,aluminum oxide, zinc oxide, or zirconium dioxide for diffusing the lightemitted from the light-emitting structure 11. The weight percentage(w/w) of the diffusing powder within the matrix is between 0.1%˜0.5% andhas a particle size between 10 nm˜100 nm or between 10 μm˜50 μm. In anembodiment, the weight percentage of the diffusing powder (or thewavelength-conversion particles) within the matrix can be measured by athermogravimetric analyzer (TGA). Specifically, the matrix is removed(through evaporation or pyrolysis) by increasing the temperature to acertain temperature so the diffusing powder (or thewavelength-conversion particles) is remained. The change of the weightcan be measured and the weight of the matrix and the weight of thediffusing powder (or the wavelength-conversion particles) can berespectively derived from the change of the weight, and the weightpercentage of the diffusing powder within the matrix can be calculated.Or, the total weight of the matrix and the diffusing powder (or thewavelength-conversion particles) can be measured first, and a solvent isapplied to remove the matrix so the weight of the diffusing powder (orthe wavelength-conversion particles) can be measured. Then, the weightpercentage of the diffusing powder (or the wavelength-conversionparticles) within the matrix can be calculated.

The wavelength-conversion particles 131 can absorb a first light emittedfrom the light-emitting structure 11 and convert the first light to asecond light having a spectrum different from that of the first light.The first light is mixed with the second light to produce a third light.In this embodiment, the third light has chromaticity coordinates (x, y)on CIE 1931 chromaticity diagram, wherein 0.27≦x≦0.285; 0.23≦y≦0.26. Inanother embodiment, the first light is mixed with the second light toproduce a third light, such as a white light. Based on the weightpercentage and the material of the wavelength-conversion particles, thelight-emitting device has a correlated color temperature of about2200K˜6500K (ex. 2200K, 2400K, 2700K, 3000K, 5000K˜5700K, 6500K) under athermal stable state with a color point (CIE x, y) within a seven-stepMacAdam ellipse. In another embodiment, the first light is mixed withthe second light to produce purple light, amber light, green light,yellow light or other non-white light.

In FIGS. 1A-1C, the first side surface 123 and the third side surface125 are covered by the second reflective layer 17, and the bottomsurface 122 is covered by the first reflective layer 14 and theextension electrode layers 15A, 15B, therefore, the light-emittingdevice 100 has three light emitting surfaces. In other words, the lightemitted from the light-emitting structure 11 pass directly through thetop surface 121, the second side surface 124 and the fourth side surface126 of the light-transmitting body 12 to exit the light-emitting device100. The light-emitting angle, which will be described later, of thelight-emitting structure 11 is about 140° so more than 50% of lightemits outward from the top surface 1101 (or the top surface 121 of thelight-transmitting body 12). The top surface 1101 of the light-emittingstructure 11 is defined as a main light-emitting surface. Thelight-emitting directions of the light-emitting structure 11 and thelight-emitting device 100 are identical, that is, light emit outwardalong the Z axis (exiting the light-emitting device 100). Accordingly,the main light-emitting surface of the light-emitting structure 11 andthe light-emitting surface of the light-emitting device 100 aresubstantially parallel to each other.

FIGS. 2A˜2C show cross-sectional views of light-emitting devices 100′,100″, 100′″ in accordance with embodiments of the present disclosure,respectively. Each of the light-emitting devices 100′, 100″, 100′″ has astructure similar to that of the light-emitting device 100, and devicesor elements with similar or the same symbols represent those with thesame or similar functions. As shown in FIG. 1C, FIGS. 2A˜2C showcross-sectional views taken along lines II-II of FIG. 1A. Thecorresponding bottom view can be referred to FIG. 1A and thecorresponding cross-sectional views taken along lines I-I can bereferred to FIGS. 1B and 1D.

Referring to FIG. 2A, the second reflective layer 17′ has an outersurface 171′ and an inner surface 172′. The outer surface 171′ issubstantially perpendicular to top surface 121 and the inner surface172′ has a curved shape. Specifically, a distance (D1) between the innersurface 172′ and the outer surface 171′ is gradually decreased in adirection from the top surface 121 to the bottom surface 122 of thelight-transmitting body 12. Moreover, the inner surface 171′ connects tothe outer surface 171′.

Referring to FIG. 2B, the second reflective layer 17″ has an outersurface 171″ and an inner surface 172″. The outer surface 171″ is asurface perpendicular to top surface 121 and the inner surface 172″ hasa curved shape. Specifically, a distance (D1) between the inner surface172″ and the outer surface 171″ is gradually increased in a directionfrom the top surface 121 to the bottom surface 122 of thelight-transmitting body 12.

Referring to FIG. 2C, the second reflective layer 17′″ has an outersurface 171′″ and an inner surface 172′″. The outer surface 171′″ andthe inner surface 172′″ are substantially perpendicular to the topsurface 121.

FIG. 2D show a cross-sectional view of light-emitting device 200 inaccordance with an embodiment of the present disclosure. Thelight-emitting device 200 has a structure similar to that of thelight-emitting device 100, and devices or elements with similar or thesame symbols represent those with the same or similar functions. In thisembodiment, the second reflective layer 27 includes metal such as Au,Ag, Cu, Al, Pt, Ni, or Rh. Accordingly, reflection of the light emittedfrom the light-emitted structure 11 occurs at the second reflectivelayer 27 and the reflection is called specular reflection. In addition,when the second reflective layer 27 is metal and has a thickness of50˜200 Å, its reflectivity is 99% so a thickness of the light-emittingdevice 200 in the Y direction can be reduced and the applicability ofthe light-emitting device 200 (for example, mobile phone, liquid crystaldisplay, wearable apparatus (watch, wristband, ring, etc.)) is thereforeincreased. The second reflective layer 27 can be formed on thelight-transmitting body 12 by sputtering, electroplating or chemicalplating. Alternatively, an adhesive (not shown), such as TiO₂, can beformed between the second reflective layer 27 and the light-transmittingbody 12 for improving adhesion therebetween. Or, the light-transmittingbody 12 is undergone a surface treatment (for example, He plasma, O₂plasma, or N₂ plasma) and the second reflective layer 27 is immediatelyformed thereon (that is, the second reflective layer 27 contactsdirectly the light-transmitting body 12). The surface treatment improvesadhesion between the second reflective layer 27 and thelight-transmitting body 12.

The cross-sectional shape of the second reflective layer is determinedby the shape and size of a cutter used in the process. When the cutterhas a curved shape in cross section, the second reflective layer has acurved inner surface (shown in FIGS. 1C, 2A and 2B). When the cutter hasa straight-line shape in cross section, the second reflective layer hasa straight-line inner surface (shown in FIGS. 2C, 2D). Of course, thecurvature of the curved shape is also determined by the shape and thesize of the cutter. In addition, the shape of the inner surface of thesecond reflective layer affects the light intensity of thelight-emitting device. Generally speaking, compared to the straight-lineshape in cross section, more light can exit the light-emitting devicewhile the light-emitting device has the second reflective layer havingthe inner surface with the curved shape in cross section. Furthermore,the light-emitting device of FIG. 2B has a light intensity (for example,luminous flux (lumen)) greater than that of FIG. 2A or FIG. 1C.

Referring to FIG. 1A, since the second reflective layer 17 covers merelythe first side surface 123 and the third side surface 125, the lightemitted from the light-emitting structure 11 toward the first sidesurface 123 and the third side surface 125 is reflected by the secondreflective layer 17. On the contrary, the light toward the second sidesurface 124 and the fourth side surface 126 exit directly from thelight-emitting device 100. Therefore, the light-emitting device hasdifferent light-emitting angle in different directions. Furthermore,FIG. 1F shows a drawing of how to measure the lighting apparatus 100. Agoniophotometer (product numbered LID-100CS from AMA Optoelectronics.Inc.) is used to measure the luminous intensities of each points oncircle P1 or P2 while the lighting apparatus 100 emits light, whereinthe circles P1 and P2 are virtual and are defined for measurement. Theluminous intensity of each point on circle P1 is measured with an angleto obtain a first luminous intensity distribution curve and to derive afirst light-emitting angle. Likewise, the luminous intensity of eachpoint on circle P2 o is measured with an angle to obtain a secondluminous intensity distribution curve and to derive a secondlight-emitting angle. The detailed description of circles P1 and P2 canbe referred to the content disclosed in the TW patent application105114875. The first light-emitting angle is greater than the secondlight-emitting angle. In one embodiment, the first light-emitting angle(the long side, X direction) is of 130˜150°, and the secondlight-emitting angle (the short side, Y direction). Or, a difference ofthe first light-emitting angle and the second light-emitting angle isgreater than 15° and of 15˜40°. The light-emitting angle is defined as arange of angle from the angle of maximum luminous intensity to the angleof half (50%) of the maximum luminous intensity. The detaileddescription of the light-emitting angle can be referred to the contentdisclosed in the TW patent application 103104105.

Two light-emitting bodies in FIG. 1A are electrically connected inseries. In another embodiment, the light-emitting structure 11 caninclude one light-emitting body and more than three light-emittingbodies which are electrically connected in series, in parallel orseries-parallel or bridge. When the light-emitting structure includes aplurality of light-emitting bodies, the plurality of light-emittingbodies can be commonly formed on one substrate, or each of the pluralityof light-emitting bodies has a substrate and then being mounted on acarrier. Alternatively, some of the light-emitting bodies are commonlyformed on a substrate, and other light-emitting bodies have respectivesubstrates and then are mounted commonly on a carrier. In addition, twolight-emitting bodies in this embodiment are flip-chip structures andare electrically connected to each other by a conductive layer. Inanother embodiment, two light-emitting bodies are horizontal structureand are electrically connected to each other through wire bonding.

When the aforesaid light-emitting body has a hetero-structure, thefirst-type semiconductor layer and the second-type semiconductor layer,for example a cladding layer or a confinement layer, provide holes andelectrons, respectively, and each type layer has a bandgap greater thanthat of the active layer, thereby increasing the probability ofelectrons and holes combining in the active layer to emit light. Thefirst-type semiconductor layer, the active layer, and the second-typesemiconductor layer can be made of III-V group semiconductor materials,such as Al_(x)In_(y)Ga_((1-x-y))N or Al_(x)In_(y)Ga_((1-x-y))P, wherein0≦x, y≦1; (x+y)≦1. Depending on the material of the active layer, thelight-emitting diode can emit a red light with a peak wavelength ordominant wavelength of 610˜650 nm, a green light with a peak wavelengthor dominant wavelength of 530˜570 nm, a blue light with a peakwavelength or dominant wavelength of 450˜490 nm, a purple light with apeak wavelength or dominant wavelength of 400˜440 nm, or a UV light witha peak wavelength of 200˜400 nm.

FIGS. 3A˜3G show cross-sectional views of making a light-emitting devicein accordance with an embodiment of the present disclosure. FIGS. 4A˜4Gshow top views of FIGS. 3A˜3G, respectively. FIGS. 3A˜3G cross-sectionalview taken along lines W-W of FIGS. 4A˜4G, respectively. Forsimplification, the light-emitting structure 11 is shown as cuboid inFIGS. 2A˜2J for exemplary illustration. The shape of the light-emittingstructure 11 in top view can also be trapezoid, parallelogram, diamond,triangle, pentagon, hexagon, or round. For clear illustration, eachlayer is drawn in solid lines regardless of an opaque, transparent, ortranslucent material.

Referring to FIGS. 3A and 4A, a carrier 22 is provided, an adhesionlayer 21 is attached to the carrier 22 and a plurality of light-emittingstructure 11 is disposed on the adhesion layer 21. In the embodiment,the light-emitting structure 11 is attached to the adhesion layer 21through the firs electrode layer 1118 and the second electrode layer1119. The number and arrangement of the light-emitting structure 11 isillustrative, and not intended to limit the scope of the presentdisclosure.

Referring to FIGS. 3B and 4B, a transparent body including a pluralityof wavelength conversion particles 131 covers the light-emittingstructure 11 completely. The transparent body can be formed on thelight-emitting structure 11 by spraying, coating, dispensing or screenprinting. Thereafter, the transparent body is cured to form thelight-transmitting body 12. If the transparent body is formed on thelight-emitting structure 11 by spraying or dispensing, the transparentbody has various heights (Z direction) at different locations across itswhole area. After curing, the transparent body is cured to form thelight-transmitting body 12 with different heights at differentlocations. Therefore, a physical removal process is conducted toplanarize the light-transmitting body 12 so the top surface 121 of thelight-transmitting body 12 is substantially flat. The definition of “thephysical removal process” and “the substantially flat” will be describedlater.

Moreover, in this embodiment, because of gravity, during the curing, thewavelength conversion particles 131 are naturally precipitated and thusmost of the wavelength conversion particles 131 can contact thelight-emitting structure 11 and a portion of the wavelength conversionparticles 131 is attached to the side surface of the light-emittingstructure 11 (the detailed description is referred to FIGS. 1B and 1C).In another embodiment, it is possible to control the temperature andtime of the curing to change distributions of the wavelength conversionparticles 131. For example, the transparent body is fully cured beforethe wavelength conversion particles 131 do not precipitate near thebottom so the wavelength conversion particles 131 are suspended withinthe light-transmitting body 12 and do not contact the light-emittingstructure 11. Or, an anti-precipitation agent (such as TiO₂) is addedinto the transparent body for preventing the wavelength conversionparticles 131 from precipitating near the bottom during curing so thewavelength conversion particles 131 can be uniformly dispersed withinthe light-transmitting body 12.

In another embodiment, the transparent body with the wavelengthconversion particles can be pre-formed as a wavelength conversion sheetand to adhere to the light-emitting structure 11. The adhesion isestablished by tightly sealing an upper mold (not shown) and a lowermold (not shown) with heat and pressure for softening the wavelengthconversion sheet. Then, the wavelength conversion sheet tightly adheresto the light-emitting structure 11. Alternatively, the air is extractedout when the upper mold is very close to the lower mold and thewavelength conversion sheet does not contact the light-emittingstructure 11. The bubble between the wavelength conversion sheet and thelight-emitting structure 11 can be eliminated and the strength of jointcan be enhanced.

Referring to FIGS. 3C, 3D and 4D, a cutter 23 is provided and a cuttingstep is performed along the cutting line L in the X direction to form aplurality of trenches 231 in the light-transmitting body 12. Thetrenches 231 have a shape corresponding to the cutter 23. For example,in this embodiment, the cutter has a curved cross-section and thereforethe trenches 231 have the curved cross-section. In addition, thelight-transmitting body 12 also has the curved cross-section, and thecurved cross-section is close to the bottom surface 122 and surroundsthe light-emitting structure 11. Moreover, a distance between the curvedcross-section and the light-emitting structure 11 is gradually decreasedin the Z direction.

Referring to FIGS. 3E and 4E, a plurality of reflective particles ismixed into a matrix to form a paste in an uncured state, wherein thepaste includes matrix and reflective particles and has a colordetermined by the reflective particles, which is generally white.Subsequently, the paste is added to cover the light-transmitting body 12and the trenches 231 wherein the trenches 231 can be completely coveredor partially covered by the paste or have bubble remaining in the paste.Then, the paste is cured to form the second reflective layer 17. Thesecond reflective layer 17 has a height greater than that of thelight-transmitting body 12. The second reflective layer 17 can be formedon the light-emitting structure 11 by spraying, coating, dispensing orscreen printing. Likewise, the second reflective layer 17 can be apre-formed sheet and adheres to the light-transmitting body 12. Thedescription of the adhesion can be referred to the aforesaid paragraphs.

Referring to FIGS. 3F and 4F, the physical removal process (polishing orcutting) is preformed to remove a portion of the second reflective layer17 to expose the light-transmitting body 12. In the embodiment, thepaste is formed by spraying or dispensing and has various heights (Zdirection) at different locations across its whole area (as shown inFIG. 3E). After curing, the paste is cured to form the second reflectivelayer 17 having different heights at different locations as well. In thephysical removal process, a portion of the second reflective layer 17 isremoved to expose the light-transmitting body 12. Furthermore, thephysical removal process is performed continuously to remove the secondreflective layer 17 and the light-transmitting body 12 simultaneously sothe height of the light-transmitting body 12 can be reduced. The heightof the light-transmitting body 12 in FIG. 3F can be equal to or smallerthan that of FIG. 3E. In addition, the second reflective layer 17 has atop surface 173 substantially coplanar with the top surface 121 of thelight-transmitting body 12. The top surfaces 121, 173 are substantiallyflat.

The definition of “substantially flat” herein is when the light-emittingdeice 100 is observed by scanning electron microscope (SEM) at 60×˜100×magnification, the surface are not substantially and severely rugged.However, when the light-emitting deice 100 is observed by scanningelectron microscope (SEM) at larger than 400× magnification, or measuredby atomic force microscope (AFM), the light-transmitting body 12 and thesecond reflective layer 17 may have rough top surfaces 121, 173. Inaddition, in this embodiment, the matrix of the light-transmitting body12 is silicone with a hardness of 30-90 (Shore D) and the matrix of thesecond reflective layer 17 is silicone with a hardness of 10-70 (ShoreD). The difference of hardnesses between the light-transmitting body 12and the second reflective layer 17 is smaller than 30. After thephysical removal process, the maximum roughness (Ra1) of the top surface121 of the light-transmitting body 12 can be slightly larger than, equalto or slightly smaller than that of the top surface 173 of the secondreflective layer 17 (Ra2). By measuring the top surface 121 of thelight-transmitting body 12 by alpha step film thickness measuringinstrument in a measuring length of 0.5 mm, the difference (defined asthe maximum roughness) between the highest point and the lowest pointamong the top surface 121 of the light-transmitting body 12 is Ra1;likewise, by measuring the top surface 173 of the second reflectivelayer 17 in a measuring length of 0.5 mm, the difference between thehighest point and the lowest point among the top surface 173 of thesecond reflective layer 17 is Ra2; wherein 2 μm≦Ra1≦15 μm; 2 μm≦Ra2≦15μm; 0≦|Ra1−Ra2|≦13 μm.

The physical removal process is conducted by machinery cutters. Thecutter can be composed of high-carbon steel, diamond, ceramic or BN.During the removal process, only water (no slurry or chemical solution)is provided to lower the temperature which is raised due to frictionbetween the cutter and the material to be cut (for example, the secondreflective layer 17 or the light-transmitting body 12), and to wash theresidue from the removed second reflective layer 17 and the removedlight-transmitting body 12. Moreover, while the cutter having a hardnesslarger than that of the second reflective layer 17 and the removedlight-transmitting body 12 is selected, a plurality of scratched lines(not shown) which can be observed by optical microscope is formedthereon. In another embodiment, by adjusting cutting parameters (forexample, cutting speed or the material of the cutter), the scratchedlines may not be observed by optical microscope.

Referring to FIGS. 3C, 4C, 5A˜5C, a cutting step is performed along thecutting line L (in the X direction and Y direction) to form a pluralityof light-emitting devices 300. Subsequently, the adhesion layer 21 isheated or is irradiated by UV radiation light so the light-emittingstructure 11 and the light-transmitting body 12 are separated from theadhesion layer 21. Alternatively, a first reflective layer 14 andextension electrode layers 15A, 15B are further formed, and the detaileddescription can be referred to other corresponding paragraphs.

Referring to FIGS. 3C and 4C, by cutting at different locations, arelative position between the light-transmitting body 12 and thelight-emitting structure 11 is varied, that is, a distance between thefirst side surface 1103 and the first side surface 123 and a distancebetween the third side surface 1105 and the third side surface 124(referring to FIG. 1A) are changed. Then, referring to FIGS. 3F and 4F,the second reflective layer 17 is filled into the trenches 231 andcovers the side surfaces of the light-transmitting body 12. When lightemitted from the light-emitting structure 11 emits toward the secondreflective layer 17, the light is reflected or refracted at an interfacebetween the light-transmitting body 12 and the second reflective layer17 (for example, the first side surface 123 of the light-transmittingbody 12 or the inner surface 172 of the second reflective layer 17). Inconclusion, by controlling the step of FIG. 3C, a light-emitting devicewith desired far field pattern and light intensity (for example,luminous flux (lumen)) can be obtained.

FIGS. 6A˜6B show cross-sectional views of a second reflective layer inaccordance with an embodiment of the present disclosure. After cutting(shown in FIG. 3D), an upper mold 251 and a lower mold 252 are provided.A carrier 22 is mounted on the upper mode 251 and the uncured paste isfilled in a recess 2521 of the lower mold 252. The upper mold is closeto the lower mold to conduct a compressing molding so the paste coversthe light-transmitting body 1 and completely filled in the trenches 231.A heat process is conducted to cure the paste to form the secondreflective layer 17. Due to the formation of the second reflective layer17 by molding in the embodiment, the second reflective layer 17 on thelight-transmitting body 12 has the same height at different locations.The subsequent processes can be referred to the description of FIGS.3F˜3G.

FIGS. 7A˜7G show cross-sectional views of making a light-emitting device400 in accordance with an embodiment of the present disclosure. The topviews can be referred to FIGS. 4A˜4G.

Referring to FIG. 7A, a carrier 22 is provided, an adhesion layer 21 isattached to the carrier and a plurality of light-emitting structure isdisposed on the adhesion layer 21. In the embodiment, the light-emittingstructure 11 is attached to the adhesion layer 21 through the firselectrode layer 1118 and the second electrode layer 1119. In addition,the carrier 22 is mounted on the upper mold 251 and the substrate 110 ofthe light-emitting structure 11 faces toward the lower mold 252. Atransparent body with a plurality of wavelength conversion particles isfilled into the recess 2521 of the lower mold 251. Then, a compressionmolding is conducted so the transparent body covers the light-emittingstructure 11 completely. Because of gravity, during curing, thewavelength conversion particles 131 precipitate close to the bottom ofthe mold 252. Accordingly, while the transparent body is fully cured,the wavelength conversion particles 131 accumulate at the top surface121 of the light-transmitting body 12. In another embodiment, bycontrolling the temperature and time of the curing, the transparent bodyis fully cured to form the light-transmitting body 12 before thewavelength conversion particles 131 precipitate close to the bottom ofthe mold 252. Or, an anti-precipitation agent is added into thetransparent body (such as TiO₂) for preventing the wavelength conversionparticles 131 from precipitating near the bottom during curing.

Referring to FIGS. 7B˜7D, an adhesion layer 26 attaching to a carrier 27is provided. After attaching the light-transmitting body 12 in thestructure of FIG. 7B to the adhesion layer 26, the adhesion layer 21 isheated or is irradiated by UV radiation light so the light-emittingstructure 11 and the light-transmitting body 12 are separated from theadhesion layer 21 (the adhesion layer 21 and the carrier 22 are notshown in FIG. 7C) to expose the electrode layers 1118, 1119 (theelectrode layer 1119 is not shown in the figure). An electrode layer 211is formed on the electrode layers 1118, 1119. The electrode layer 211can formed on the electrode layers 1118, 1119 of a single light-emittingstructure 11, respectively. Alternatively, the electrode layer 211 canbe formed on the electrode layer 1118 of one light-emitting structureand the electrode layer 1119 of adjacent light-emitting structure toelectrically connect these light-emitting structures in series (notshown). Furthermore, a cutter 23 is provided and a cutting step isperformed along the cutting line L to form a plurality of trenches 231in the light-transmitting body 12. The trenches 231 have a shapecorresponding to the cutter 23. For example, in this embodiment, thecutter has a curved cross-section and therefore the trenches 231 havethe curved cross-section.

Referring to FIGS. 7E and 7F, likewise, the carrier 27 is mounted on theupper mode 251 and the uncured paste is filled in a recess 2521 of thelower mold 252. Then, a compression molding is conducted so the uncuredpaste covers light-transmitting body 12, the electrode layer 211 andcompletely filled in the trenches 231. A heating process is conducted tocure the paste to form the second reflective layer 17. Due to theformation of the second reflective layer 17 by molding in theembodiment, the second reflective layer 17 on the light-transmittingbody 12 has the same height at different locations. In addition, thesecond reflective layer 17 has a height higher than that of thelight-transmitting body 12.

Referring to FIG. 7G, the physical removal process (polishing orcutting) is preformed to remove a portion of the second reflective layer17 to expose the electrode layer 211. Furthermore, the physical removalprocess is performed continuously so the second reflective layer 17 andthe electrode layer 211 are simultaneously removed, thereby the heightof the electrode layer 211 can be reduced. The height of the electrodelayer 211 in FIG. 7G can be equal to or smaller than that of theelectrode layer 211 in FIG. 7F. The second reflective layer 17 has a topsurface 173 substantially coplanar with the top surface 2111 of theelectrode layer 211. In this embodiment, after the physical removalprocess, the maximum roughness (Ra3) of the top surface 211 of theelectrode layer 211 can be slightly larger than, equal to or slightlysmaller than that of the top surface 173 of the second reflective layer17 (Ra4). By alpha step film thickness measuring instrument in ameasuring length of 50 μm, the difference (defined as the maximumroughness) between the highest point and the lowest point by measuringthe top surface 2111 of the electrode layer 211 is Ra3. Likewise, bymeasuring the top surface 173 of the second reflective layer 17 in ameasuring length of 50 μm, the difference between the highest point andthe lowest point among the top surface 173 of the second reflectivelayer 17 is Ra4; wherein 2 μm≦Ra3≦15 μm; 2 μm≦Ra4≦15 μm; 0≦|Ra4−Ra3|≦13μm.

Referring to FIG. 7G, a cutting step is performed along the cutting lineL to form a plurality of light-emitting devices 400 as shown in FIGS.8A˜8C. The adhesion layer 26 is heated or is irradiated by UV radiationlight so the light-emitting structure 11 and the light-transmitting body12 are separate from the adhesion layer 26. Different from thelight-emitting devices 300 of FIGS. 5A˜5C, the curved cross-section ofthe light-transmitting body 12 in the light-emitting devices 400 ofFIGS. 8A˜8C does not surround the light-emitting structure 11 and closeto the top surface 121 of the light-transmitting body 12.

The adhesion layers 21, 26 and the carriers 22, 27 are used as atemporary carrier for mounting the light-emitting structure or thelight-emitting device during manufacturing. The adhesion layers 21, 26include blue tape, thermal release sheet or tape, UV release tape orpolyethylene terephthalate (PET). The carriers 22, 27 include glass orsapphire for supporting the adhesion layers 21, 26.

FIGS. 9A˜9E show top views of making a light-emitting device 500 inaccordance with an embodiment of the present disclosure. Thecorresponding cross-sectional views can be referred to other paragraphs.

Referring to FIGS. 9A and 9B, a cutting step using a cutter (not shown)is performed along the cutting line L in the X direction and Y directionto form a plurality of trenches 231 in the light-transmitting body 12.

Referring to FIG. 9C, a second reflective layer 17 is formed to coverthe light-transmitting body 12 and completely filled in the trenches231. The formation of the second reflective layer 17 can be referred tothe aforesaid paragraphs.

Referring to FIG. 9D, the physical removal process (polishing orcutting) is preformed to remove a portion of the second reflective layer17 to expose the light-transmitting body 12. Other description can bereferred to those of FIG. 4F and not be recited herein.

Referring to FIG. 9E, a cutting step is performed along the cutting lineL (in the X direction and Y direction) to form a plurality of discretelight-emitting devices 500 as shown in FIGS. 10A˜10D. As shown in FIGS.10A and 10B, the second reflective layer 17 covers four side surfaces,and when the bottom surface 122 is also covered by the first reflectivelayer 14 and the extension electrode layers 15A, 15B, the light-emittingdevices 500 have one light-emitting surface. As shown in FIGS. 10C and10D, the second reflective layer 17 covers three side surfaces, and whenthe bottom surface 122 is also covered by the first reflective layer 14and the extension electrode layers 15A, 15B, the light-emitting devices500 have two light-emitting surfaces. Likewise, by cutting at differentlocations, the relative position between the light-transmitting body 12and the light-emitting structure 11 can be changed, and variouslight-emitting devices are formed to have desired far field pattern andlight intensity (for example, luminous flux (lumen)) for meeting variousrequirements.

Similarly, as shown in FIGS. 11A and 11B, a cutting step is performedalong the cutting line L at the interface between the light-transmittingbody 12 and the second reflective layer 17 to obtain a light-emittingdevice 600 (as shown in FIG. 11C) having the second reflective layeronly covering one side surface. In one embodiment, the second reflectivelayer 17 covers one side surface and when the bottom surface 122 is alsocovered by the first reflective layer 14 and the extension electrodelayers 15A, 15B, the light-emitting device 600 has four light-emittingsurfaces. Compared to the light-emitting device 100 of FIG. 1A, thelight-emitting device 600 has a greater light intensity (for example,luminous flux (lumen)).

FIG. 12A shows a top view of a light-emitting device 700 in accordancewith an embodiment of the present disclosure. For clear illustration,not all layers are shown and each layer is drawn in solid lineregardless of its material being non-transparent, transparent, orsemi-transparent. FIG. 12B shows a cross-sectional view taken alonglines I-I of FIG. 12A. For simplification, the light-emitting structure11 is shown as cuboid in FIGS. 12A and 12B as an exemplary illustration.FIGS. 12A and 12B show a top view and a cross-sectional view in onedirection, respectively. Other relative views and the structure of thelight-emitting structure 11 can be referred to the correspondingparagraphs in this specification and figures.

Referring to FIGS. 12A and 12B, the light-emitting device 700 includes alight-emitting structure 11, a wavelength-conversion body 13, alight-transmitting body 12, a first reflective layer 14, extensionelectrode layers 15A, 15B, and a second reflective layer 17. Thelight-emitting structure 11 includes a top surface 1101, a bottomsurface 1102 opposite to the top surface 1101, and four side surfaces (afirst side surface 1103, a second side surface 1104, a third sidesurface 1105, and a fourth side surface 1106) connecting between the topsurface 1101 and the bottom surface 1102. The wavelength-conversion body13 covers the top surface 1101, the four side surface 1103˜1106 and aportion of the bottom surface 1102. Likewise, the light-transmittingbody 12 enclose the wavelength-conversion body 13, that is, thelight-transmitting body 12 covers the top surface and four side surfacesof the wavelength-conversion body 13. The light-transmitting body 12 hasa top surface 121, a bottom surface 122 opposite to the top surface 121and four side surfaces (a first side surface 123, a second side surface124, a third side surface 15 and a fourth side surface 126) connectingbetween the top surface 121 and the bottom surface 122. The secondreflective layer 17 covers the top surface 121, the first side surface123, the second side surface 124, and the fourth side surface 126without covering the third side surface 125 and the bottom surface 122.In other words, the second reflective layer 17 cover the first sidesurface 1103, the second side surface 1104 and the fourth side surface1106 without covering the third side surface 1105.

Referring to FIGS. 12A and 12B, the light-emitting angle of thelight-emitting structure 11 is about 140° so more than 50% of lightemits outward from the top surface 1101. In that case, the top surface1101 of the light-emitting structure 11 is defined as a mainlight-emitting surface. Because the top surface 1102 and the three sidesurfaces (1103, 1104, 1106) are covered by the second reflective layer17 and the bottom surface 1102 is covered by the first reflective layer14, light emitted from the light-emitting structure 11 is reflected bythe second reflective layer 17 or/and the first reflective layer 14 andexits the light-emitting device 700 through the third side surface 1105and the third sides surface 125 of the light-transmitting body 12. Inother words, the light-emitting directions of the light-emittingstructure 11 and the light-emitting device 100 are different. Most lightemitted from the light-emitting structure 11 emits outward along the Zaxis (without exiting the light-emitting device 700), but most lightemitted from the light-emitting device 700 emits outward along the Yaxis (exiting the light-emitting device 700). Accordingly, the mainlight-emitting surface of the light-emitting structure 11 and thelight-emitting surface of the light-emitting device 700 aresubstantially perpendicular to each other.

Furthermore, in FIG. 12B, a bottom surface 174 of the second reflectivelayer 17 is substantially parallel to the top surface 173, but it doesnot limit this disclosure. Any optical design for improving lightextraction from the light-emitting device 700 can be applied in thesecond reflective layer 17. For example, directing light from thelight-emitting structure 11 toward the third side surface 1195 to exitthe light-emitting device 700 can be achieved by changing the shape ofthe top surface 121 of the light-transmitting body 12. The shape of thebottom surface 174 of the second reflective layer 17 is determined bythe shape of the top surface 121. The corresponding structure andprocess will be described later.

The light-emitting device 700 has a height (H₀) not greater than 0.3 mm(≦0.3 mm) which expands the applicability of the light-emitting device700 (for example, mobile phone, liquid crystal display, wearableapparatus like watch, wristband, or ring). As described above, thelight-emitting directions of the light-emitting structure 11 and thelight-emitting device 100 are different, and therefore when an area ofthe main light-emitting surface (XY plane) of the light-emittingstructure 11 is increased, the height of the light-emitting device 700is not increased. In addition, since the area of the main light-emittingsurface (XY plane) of the light-emitting structure 11 is increased, thelight output of the light-emitting structure 11 and the overall luminousflux are therefore enhanced. However, the height of the light-emittingdevice 700 is not increased, and the applicability of the light-emittingdevice 700 is not adversely affected.

FIGS. 13A˜13F show cross-sectional views of making a light-emittingdevice in accordance with an embodiment of the present disclosure. FIGS.14A˜14F show top views of FIGS. 13A˜13F, respectively. FIGS. 13A˜13F arecross-sectional view taken along lines W-W of FIGS. 14A˜14F,respectively. For simplification, the light-emitting structure 11 isshown as cuboid as an exemplary illustration. For clear illustration,each layer is drawn in solid lines regardless of a non-transparent,transparent, or translucent material.

Referring to FIGS. 13A and 14A, a carrier 22 is provided, an adhesionlayer 21 is attached to the carrier 22, and a plurality oflight-emitting structure 11 is disposed on the adhesion layer 21. In theembodiment, the light-emitting structure 11 is attached to the adhesionlayer 21 through the firs electrode layer 1118. The number andarrangement of the light-emitting structure 11 of FIG. 13A isillustrative, and not intended to limit the scope of the presentdisclosure.

Referring to FIGS. 13B and 14B, a wavelength conversion body 13completely covers the top surface 1101, the side surfaces 1103˜1106 anda portion of the bottom surface 1102 of the light-emitting structure 11.The wavelength conversion body 13 can be formed on the light-emittingstructure 11 by spraying, coating, dispensing, screen printing ormolding.

Referring to FIGS. 13C˜13D and 14C˜14D, a transparent body without aplurality of wavelength conversion particles completely encloses thewavelength conversion body 13. Thereafter, the transparent body is curedto form the light-transmitting body 12. The transparent body can beformed by spraying, coating, dispensing, screen printing or molding.Subsequently, a cutter 23 is provided and a cutting step is performedalong the cutting line L in the X direction and Y direction to form aplurality of trenches 231. The trenches 231 are formed within thelight-transmitting body 12 and the wavelength conversion body 13 toexpose the adhesion layer 21. In the cutting step, the trenches 231 arelocated between two adjacent light-emitting structures 11 and thelight-transmitting 12 is divided into a plurality of discontinuousareas. The light-transmitting body 12 and the wavelength conversion body13 cover the four side surfaces and the top surface of thelight-emitting structure 11.

Referring to FIGS. 13E˜13F and 14E˜14F, a plurality of reflectiveparticles is mixed into a matrix to form a paste in an uncured state.Subsequently, the paste is added to cover the light-transmitting body 12and the trenches 231 wherein the trenches 231 can be completely coveredor partially covered by the paste or have bubble remaining in the paste.Then, the paste is cured to form the second reflective layer 17. Thesecond reflective layer 17 has a height greater than that of thelight-transmitting body 12, that is, the second reflective layer 17covers the fourth side surfaces 123˜126 and the top surface 121(referring to FIGS. 12A and 12B). The second reflective layer 17 can beformed by spraying, coating, dispensing or screen printing. In anotherembodiment, the second reflective layer 17 can be a pre-formed sheet andadheres to the light-transmitting body 12. The description of theadhesion can be referred to the aforesaid paragraphs. Finally, a cuttingstep is performed along the cutting line L (in the X direction and Ydirection). Subsequently, the adhesion layer 21 is heated or isirradiated by UV radiation light so the light-emitting structure 11, thelight-transmitting body 12, the wavelength conversion body 13 and thesecond reflective layer 17 are separated from the adhesion layer 21 toform a plurality of light-emitting devices.

Referring to FIGS. 13E˜13F and 14E˜14F, the light-transmitting body 12is cut along the cutting lines L in X direction so the second reflectivelayer 17 covers merely the three side surfaces of the light-transmittingbody 12 to expose one side surface. By varying the locations of thecutting lines, the thicknesses at the two sides where thelight-transmitting body 12 covers the first side surface 1103 and thethird side surface 1105 are equal to each other or different. Forexample, when a portion of the light-transmitting body 12 is removed inthe cutting step, the thicknesses at two side of the light-transmittingbody 12 are different (T₁≠T₂). Or, by controlling the locations of thecutting lines the light-transmitting body 12 is not removed in thecutting step and the thicknesses at two side of the light-transmittingbody 12 are equal to each other.

Next, alternatively, a first reflective layer 14 and extension electrodelayers 15A, 15B as shown in FIG. 12B are further formed, and thedetailed description can be referred to other corresponding paragraphs.

FIGS. 15A˜15F show cross-sectional views of making a light-emittingdevice in accordance with an embodiment of the present disclosure. FIGS.16A˜16F show top views of FIGS. 15A˜15F, respectively. FIGS. 15A˜15F arecross-sectional view taken along lines W-W of FIGS. 16A˜16F,respectively. The detailed description of FIGS. 15A˜15B can be referredto the corresponding paragraphs of FIGS. 13A˜13B.

Referring to FIGS. 15C˜15D and 16C˜16D, a cutter 23A is provided and acutting step is performed along the cutting line L in the X direction toform a plurality of trenches 231 within the light-transmitting body 12to expose the wavelength conversion body 13. Furthermore, the cuttingstep using the cutter 23A is performed along the Y axis with a variabledepth of cut along the Z axis. Because the cutter 23A has a curvedcross-section and therefore the top surface 121 of light-transmittingbody 12 has a wavy shape cross-section.

For example, referring to FIG. 17A, the cutter 23A is locate between thelight-emitting structures 11D, 11E and cuts downward (−Z direction)until reaching the adhesion layer 21 to form the trench 231, wherein thedepth of cut is H1.

Referring to FIG. 17B, the cutter 23A moves a first distance (S1) alongthe Y axis and is located above the light-emitting structure 11E to cuta portion of the light-transmitting body 12, wherein the depth of cut isH2 (H2<H1).

Referring to FIG. 17C, the cutter 23A moves forward a second distance(S2) along the Y axis and is still located above the light-emittingstructure 11E to cut a portion of the light-transmitting body 12,wherein the depth of cut is H3 (H3>H2, H3<H1).

Referring to FIG. 17D, the cutter 23A moves forward a third distance(S3) along the Y axis and is still located above the light-emittingstructure 11E to cut a portion of the light-transmitting body 12,wherein the depth of cut is H4 (H4>H3>H2; H4<H1).

Referring to FIG. 17E, the cutter 23A moves forward a fourth distance(S4) along the Y axis and is still located above the light-emittingstructure 11E to cut a portion of the light-transmitting body 12,wherein the depth of cut is H5 (H5>H4>H3>H2; H5<H1).

Referring to FIG. 17F, the cutter 23A moves forward a fifth distance(S5) along the Y axis and is still located above the light-emittingstructure 11E to cut a portion of the light-transmitting body 12,wherein the depth of cut is H6 (H6>H5>H4>H3>H2; H6<H1).

Finally, referring to FIG. 17A, the cutter 23A moves outside thelight-emitting structure 11E (not located above the light-emittingstructure 11E) and is located between the light-emitting structures 11E,11F and cuts downward (−Z direction) until reaching the adhesion layer21 to form the trench 231, wherein the depth of cut is H1. Accordingly,the top surface 121 of light-transmitting body 12 has a wavy shapecross-section.

According to the aforesaid method, the cutter 23A moves along the Y axisand cut downward along the Z axis with various cutting depth, therebyforming the top surface 121 of light-transmitting body 12 with differentshapes. In addition, the shape of the cutter could cause differentprofile at the top surface 121. For example, as shown in FIG. 18A, thetop surface 121 of light-transmitting body 12 has a steppedcross-section; as shown in FIG. 18B, the top surface 121 oflight-transmitting body 12 has a smooth inclined surface in crosssection; as shown in FIG. 18C, the top surface 121 of light-transmittingbody 12 has a serrated cross-section.

Furthermore, by cutting at different locations, the top surface 121 oflight-transmitting body 12 can have various shapes. As shown in FIG.18D, the cutter is moved to locate above the light-emitting structureand cut downward, and the light-transmitting body 12 has a first surface127 substantially parallel to the top surface 173 and a second surface128 inclined with respect to the top surface 173. The first surface 127and the second surface 128 have a portion above the light-emittingstructure. Compared to the light-transmitting body 12 having the topsurface 121 substantially perpendicular to the top surface 173 shown inFIG. 12, the top surface 121 of the light-transmitting body 12 above thelight-emitting structure in FIG. 18D is not partially or entirelyparallel to the top surface 173 (for example, inclined surface, a wavyshape, stepped, etc.) that can help to reflect light from thelight-emitting structure toward the side surface to exit thelight-emitting device for increasing light intensity.

As shown in FIG. 18E, the top surface 121 of the light-transmitting body12 having the first surface 127 and the second surface 128 can beobtained by using a non-symmetric cutter. In addition, only one cuttingstep is conducted to form the structure shown in FIG. 18E. Therefore,compared to the processes described in FIGS. 17A-17E, the processdisclosed in this embodiment is simpler and processing time and cost canbe reduced.

Referring to FIGS. 15E˜15F and 16E˜16F, a plurality of reflectiveparticles is mixed into a matrix to form a paste in an uncured state.The paste covers the light-transmitting body 12 and the trenches 231wherein the trenches 231 can be completely covered or partially coveredby the paste or have bubble remaining in the paste. Then, the paste iscured to form the second reflective layer 17. Other description of thesecond reflective layer 17 can be referred to the correspondingparagraphs. Subsequently, a cutting step is performed along the cuttingline L (in the X direction and Y direction). Thereafter, the adhesionlayer 21 is heated or is irradiated by UV radiation light for removal soa plurality of light-emitting devices is formed.

Referring to FIG. 15F, the light-transmitting body 12 is cut along thecutting lines L in X direction so the second reflective layer 17 coversmerely the three side surfaces of the light-transmitting body 12 toexpose one side surface of the light-transmitting body 12. In addition,because the top surface 121 of the light-transmitting body 12 has a wavyshape, the bottom surface 174 of the second reflective layer 17, whichcontacts the top surface 121 of the light-transmitting body 12, also hasa wavy shape.

FIG. 19 shows a cross-sectional view of a light-emitting device 800 inaccordance with an embodiment of the present disclosure. Forsimplification, the light-emitting structure 11 is shown as cuboid inFIG. 19 as an exemplary illustration.

The light-emitting device 800 has a structure similar to that of thelight-emitting device 100, and devices or elements with similar or thesame symbols represent those with the same or similar functions. FIG. 19only shows a cross-sectional view of the light-emitting device 800 andother views can be referred to the description of the light-emittingdevice 100. The light-emitting device 800 includes a light-emittingstructure 11, a light-transmitting body 12 including a plurality ofwavelength conversion particles, a first reflective layer 14, extensionelectrode layers 15A, 15B, and a second reflective layer 17.

The structure of FIG. 19 is similar to that of FIG. 2, except the shapeof the second reflective layer. As shown in FIG. 19, the secondreflective layer 17A has an outer surface 171A and an inner surface172A. The outer surface 171A is substantially perpendicular to the topsurface 121 and the inner surface 172A has a first portion 172A1inclined with respect to the top surface 121 and a second portion 172A2substantially perpendicular to the top surface 121. The first portion172A1 extends from the first reflective layer 14 along the Z axis andhas a height higher than the light-emitting structure 11. The firstportion 172A1 can reflect light from the light-emitting structure 11toward the light-transmitting body 12 to exit the light-emitting device800. The first side surface 123 and the third side surface 125 contactdirectly the inner surface 172A of the second reflective layer 17A sothe shapes of the first side surface 123 and the third side surface 125are the same as that of the inner surface 172A of the second reflectivelayer 17A. The first portion 172A1 is inclined with respect to the firstreflective layer 14 with an angle (θ) of 60°˜80°. The second portion172A2 extends from the first portion 172A1 along the Z axis.

FIGS. 19A˜19C show simplified cross-sectional views of light-emittingdevices. The simplified light-emitting devices are used in thesimulation for obtaining a relation among the height of the firstportion (μm) 172A1, the height of the second portion (μm) 172A2, theangle (θ), and the luminous flux (mW). Table 1 shows the simulationresult of different angles and the luminous fluxs. In the simulation,the thickness (Y direction) of the light-emitting device is set to 1.1mm and the height (Z direction) is 0.35 mm. As shown in Table 1, whenthe angle (θ) is increased, light emitted from the light-emittingstructure 11 are not prone to be reflected at the first portion 172A1toward the light-transmitting body 12 to exit the light-emitting device,which results in lower luminous flux. In addition, since the secondportion 172A2 is located above the first portion 172A1 which makes thelight-emitting areas (Ea) of the three light-emitting devices withdifferent angles equal, the light-emitting angles of the light-emittingdevices in FIGS. 19A˜19C are substantially the same. As mentioned above,the inclined angled (θ) can change the luminous flux of thelight-emitting device and the light-emitting angle of the light-emittingdevice can be fixed to a specific value by virtue of the second portion172A2. In other words, by the first portion and the second portion, thelight-emitting device could have a predetermined luminous flux and apredetermined light-emitting angle.

TABLE 1 Height of the first Height of the Luminous flux portion(μm)second portion(μm) Angle( θ ) (mW) 250 100 60 7.4 250 100 70 7.37 250100 80 7.33

When the height of the light-emitting device is fixed, if the inclinedangle (θ) is increased, the thickness (Y direction) of thelight-emitting device is increased. The light-emitting device may not beprone to apply in some areas due to its larger size. Accordingly, it isnecessary to consider the applications while designing the inclinedangle.

FIGS. 20A˜20G show cross-sectional views of making a light-emittingdevice in accordance with an embodiment of the present disclosure. FIGS.21A˜21G show top views of FIGS. 20A˜20G, respectively. FIGS. 20A˜20G arecross-sectional views taken along lines W-W of FIGS. 21A˜21G,respectively. For simplification, the light-emitting structure 11 isshown as cuboid as an exemplary illustration. For clear illustration,each layer is drawn in solid lines regardless of a non-transparent,transparent, or translucent material. The detailed description of FIGS.20A˜20B and FIGS. 21A˜21B can be referred to the correspondingparagraphs of FIGS. 3A˜3B and FIGS. 4A˜4B.

Referring to FIGS. 20C˜20D and FIGS. 21C˜21D, an adhesion layer 26 isprovided for attaching to a carrier 27. After attaching the structure ofFIG. 20B to the adhesion layer 26, wherein the light-transmitting body12 is attached to the adhesion layer 26, the adhesion layer 21 is heatedor is irradiated by UV radiation light so the light-emitting structure11 and the light-transmitting body 12 are separated from the adhesionlayer 21 (the adhesion layer 21 and the carrier 22 are not shown in FIG.20C) to expose the electrode layers 1118, 1119 (the electrode layer 1119is not shown in the figure).

Subsequently, a first cutter 23B is provided and a cutting step isperformed along the cutting line L (X direction) to cut thelight-transmitting body 12. The first cutter 23B has a trianglecross-section and the cutting depth (H7) is smaller than the height (Zdirection) of the light-transmitting body 12 but larger than the heightof the light-emitting structure 11. Since the light-transmitting body 12is not completely cut off, portions of the light-transmitting body 12are connected to each other.

Referring to FIGS. 20D, 20E, 21D, and 21E, a second cutter 23A isprovided to cut downward until reaching the adhesion layer 26 so thelight-transmitting body 12 is completely cut off to form the trench 231.

Referring to FIGS. 20F˜20G and FIGS. 21F˜21G, a plurality of reflectiveparticles is mixed into a matrix to form a paste in an uncured state.The paste covers the light-transmitting body 12 and the trenches 231wherein the trenches 231 can be completely covered or partially coveredby the paste or have bubble remaining in the paste. Then, the paste iscured to form the second reflective layer 17. Other description of thesecond reflective layer 17 can be referred to corresponding paragraphs.Subsequently, a cutting step using the second cutter 23A is performedalong the cutting line L (in the X direction and Y direction).Thereafter, the adhesion layer 26 is heated or is irradiated by UVradiation light so the light-emitting structure 11, thelight-transmitting body 12, and the second reflective layer 17 areseparated from the adhesion layer 26 to form a plurality oflight-emitting devices.

Since the paste is filled to cover the light-transmitting body 12 andwithin the trenches, in this step, the paste may cover a portion of theelectrode layers 1118, 1119 (the electrode layer 1119 is not shown inthe figure). In another embodiment, a protective layer (for example,photoresist, not shown) is formed on the electrode layer 1118 prior tofilling the paste such that the paste can cover the protective layerwithout contacting directly the electrode layers 1118, 1119. Thereafter,the protective layer is removed to expose the electrode layers 1118,1119. A cleaning step to clean the electrode layers 1118, 1119 can beeliminated while using the protective layer. Alternatively, a firstreflective layer 14 and extension electrode layers 15A, 15B are furtherformed, and the detailed description can be referred to othercorresponding paragraphs.

In FIGS. 20A˜20G, two cutters with different heads are used to form thelight-transmitting body 12 with the first surface 172A1 and the secondsurface 172A2 (referring to the description of FIG. 19). However, thecutter can have a specific shape so one cutting step is performed toobtain the same structure as which is obtained by conducting two cuttingsteps of FIGS. 20C and 20D.

FIG. 22A shows a cross-sectional view of a light-emitting device 900 inaccordance with an embodiment of the present disclosure. Referring toFIG. 22, the second reflective layer 17B has an outer surface 171B andan inner surface 172B. The outer surface 171B is substantiallyperpendicular to the top surface 121, and the inner surface 172B isinclined with respect to the top surface 121. The inner surface 172Bextends from the first reflective layer 14 to the top surface 121 of thelight-transmitting body 12 along the Z axis. The inner surface 172B isinclined with respect to the first reflective layer 14 with an angle (θ)of 60°˜80°. The inner surface 172B can reflect light from thelight-emitting structure 11 toward the top surface 121 of thelight-transmitting body 12.

FIG. 22B shows a cross-sectional view of a light-emitting device 1000 inaccordance with an embodiment of the present disclosure. FIG. 22C showsa cross-sectional view of a light-emitting device 1100 in accordancewith an embodiment of the present disclosure. Referring to FIGS. 22B and22C, the second reflective layer 17C has an outer surface 171C and aninner surface 172C. The outer surface 171C is substantiallyperpendicular to the top surface 121, and the inner surface 172C isinclined with respect to the top surface 121. The inner surface 172Cextends from the first reflective layer 14 along the Z axis withoutcontacting the top surface 121 of the light-transmitting body 12. Theinner surface 172C is separated from the top surface 121 by a distance(D2); wherein 1 μm≦D2≦800 μm (D2=20 μm, 50 μm, 100 μm, 200 μm, 300 μm,400 μm, 500 μm, 600 μm, 700 μm). The light-emitting device withdifferent D2 can be applied to different applications. In other words, aportion of the first side surface 123 (or the third side surface 125) isnot covered by the second reflective layer 17 and is exposed toenvironment. The exposed first side surface 123 (or the third sidesurface 125) is substantially coplanar with the outer surface 171C ofthe second reflective layer 17. As shown in FIGS. 22B and 22C, since thelight-transmitting body 12 covers the second reflective layer 17, in thetop view, the light-transmitting body 12 is seen directly and the secondreflective layer 17 is not seen. The inner surface 172C can reflectlight from the light-emitting structure 11 toward the top surface 121 ofthe light-transmitting body 12.

In FIG. 22B, the inner surface 172C is higher than the light-emittingstructure 11. In FIG. 22C, the inner surface 172C is lower than thelight-emitting structure 11. As shown in FIG. 22C, the inner surface172C has a height (D3) and the light-emitting structure 11 has a height(D4); ΔD=D3−D4. Table 2 shows the experimental result of ΔD and thelight-emitting angle of the light-emitting device.

TABLE 2 Δ D Light-emitting D2 (um) D3 (um) D4 (um) Angle ( θ ) (um)angle 280 70 150 60 −80 140 210 140 150 60 −10 135 150 200 150 60 50 120120 230 150 60 80 120 70 280 150 60 130 130

As shown in Table 2, when D3<D4 and the absolute value of ΔD becomeslarger, the light-emitting angle of the light-emitting device 1100 alsobecomes larger, and the light-emitting angle of the light-emittingdevice 1100 is close to that where the light-emitting device 1100 doesnot have the light-transmitting body 12. Different from FIG. 19, inFIGS. 22B and 22C, the inner surface 172C does not extend to the topsurface 121, that is, the light-transmitting body 12 is located on theinner surface 172C and there is no the second portion (172A2) as shownin FIG. 19. As shown in FIG. 22B, when the inner surface 172C has aheight higher than that of the light-emitting structure 11, light fromthe light-emitting device 1000 is reflected by the inner surface 172Ctoward the light-transmitting body 12 to exit the light-emitting device1000. The light-emitting angle of the light-emitting device 1100 can bedecreased (for example, from 140° to 120°) through the inner surface172C. On the contrary, as shown in FIG. 22C, when the inner surface 172Chas a height lower than that of the light-emitting structure 11, since aportion of light from the light-emitting device 1100 is not reflected bythe inner surface 172C and exits directly the light-emitting device1100, the light-emitting angle of the light-emitting device 1100 islarger than that of the light-emitting device 1000 but smaller than thatof the light-emitting structure 11 (for example, the light-emittingangle of the light-emitting device 1100 is larger than 120° and smallerthan 140°). By designing the height of the inner surface 172C, thelight-emitting device can have various light-emitting angles forimproving its applicability.

Moreover, as table 1 and table 2 show, by having the first portion 172A1and the second portion 172A2 (see FIG. 19) or the inclined surface(inner surface 172C) with a height higher than that of thelight-emitting structure, the light-emitting device can have apredetermined light-emitting angle (for example, 120°) which is smallerthan the light-emitting angle of the light-emitting structure 11.However, compared to the light-emitting device with the secondreflective layer having merely the inner surface perpendicular to thetop surface 121 (see FIG. 2C) or the light-emitting device without thesecond reflective layer, the light-emitting device with the secondreflective layer having merely the inclined surface (regardless of theheight higher or lower than the light-emitting structure) has animproved light intensity.

FIGS. 23A˜23F show cross-sectional views of making a light-emittingdevice in accordance with an embodiment of the present disclosure. FIGS.24A˜24F show top views of FIGS. 23A˜23F, respectively. FIGS. 23A˜23F arecross-sectional view taken along lines W-W of FIGS. 24A˜24F,respectively. For simplification, the light-emitting structure 11 isshown as cuboid as an exemplary illustration. For clear illustration,each layer is drawn in solid lines regardless of a non-transparent,transparent, or translucent material. The detailed description of FIGS.23A˜23B and FIGS. 24A˜24B can be referred to the correspondingparagraphs of FIGS. 3A˜3B and FIGS. 4A˜4B.

Referring to FIGS. 23C˜23D and FIGS. 24C˜24D, an adhesion layer 26 isprovided for attaching to a carrier 27. After attaching the structure ofFIG. 23B to the adhesion layer 26 wherein the light-transmitting body 12is attached to the adhesion layer 26, the adhesion layer 21 is heated oris irradiated by UV radiation light so the light-emitting structure 11and the light-transmitting body 12 are separated from the adhesion layer21 (the adhesion layer 21 and the carrier 22 are not shown in FIG. 23C)to expose the electrode layers 1118, 1119 (the electrode layer 1119 isnot shown in the figure).

Subsequently, a cutter 23B is provided and a cutting step is performedalong the cutting line L (X direction) to cut the light-transmittingbody 12 until reaching the adhesion layer 26 (which means the cuttingdepth (H8) is substantially equal to the height of thelight-transmitting body 12) to form trenches 231. The light-transmittingbody 12 is divided into a plurality of disconnected areas (A1˜A3).

Referring to FIGS. 23E˜23F and FIGS. 24E˜24F, a plurality of reflectiveparticles is mixed into a matrix to form a paste in an uncured state.The paste covers the light-transmitting body 12 and the trenches 231wherein the trenches 231 can be completely covered or partially coveredby the paste or have bubble remaining in the paste. Then, the paste iscured to form the second reflective layer 17. Other description of thesecond reflective layer 17 can be referred to corresponding paragraphs.Subsequently, a cutting step is performed along the cutting line L (inthe X direction and Y direction). Thereafter, the adhesion layer 26 isheated or is irradiated by UV radiation light so the light-emittingstructure 11, the light-transmitting body 12, and the second reflectivelayer 17 are separated from the adhesion layer 26 to form a plurality oflight-emitting devices.

In one embodiment, during cutting, the light-transmitting body 12 andthe second reflective layer 17 are simultaneously cut, and therefore aportion of the light-transmitting body 12 is not covered by the secondreflective layer 17 and is exposed to environment (the detaileddescription can be referring to FIG. 22B). Or, cutting at differentlocations can alter the height of the second reflective layer 17, thecontact area between the light-transmitting body 12 and the secondreflective layer 17, or the exposed area (height) of thelight-transmitting body 12. In addition, cutting at different locationsto cut merely the second reflective layer 17 can also make the secondreflective layer 17 cover the light-transmitting body 12 as shown inFIG. 22A.

FIGS. 25A˜25D show perspective views of making a light-emitting devicein accordance with an embodiment of the present disclosure. FIGS.26A˜26C show cross-sectional views of FIGS. 25B˜25D, respectively. Forsimplification, the light-emitting structure 11 is shown as cuboid as anexemplary illustration. For clear illustration, each layer is drawn insolid lines regardless of a non-transparent, transparent, or translucentmaterial.

Referring to FIG. 25A, a carrier 22 is provided, an adhesion layer 21 isattached to the carrier 22 and a plurality of light-emitting structure11 is disposed on the adhesion layer 21. In the embodiment, thelight-emitting structure 11 is attached to the adhesion layer 21 throughthe firs electrode layer 1118 and the second electrode layer 1119. Thenumber and arrangement of the light-emitting structure 11 of FIG. 25A isillustrative, and not intended to limit the scope of the presentdisclosure.

Referring to FIGS. 25B and 26A, a reflective frame 37 with a pluralityof through holes is provided and is disposed on the adhesion layer 21 sothe light-emitting structures 11 is located within the through holes andthe reflective frame 37 surrounds the light-emitting structures 11. Thereflective frame 37 and the adhesion layer 21 cooperated with each otherto form a recess 38. The reflective frame 37 has an inclined inner wall371.

Referring to FIGS. 25C and 26B, a transparent body including a pluralityof wavelength conversions particles is filled into the recess andcompletely covers the light-emitting structures 11. Then, thetransparent body is cured to form the light-transmitting body 12.

Referring to FIGS. 25D and 26C, a cutting step is performed along the Xdirection to cut the reflective frame 37 and along the Y direction tocut the light-transmitting body 12 and the reflective frame 37 to form aplurality of light-emitting devices. Similarly, during cutting, if onlythe reflective frame 37 (the second reflective layer 17) is cut, thelight-emitting device 900 of FIG. 22A is obtained. Or, if thelight-transmitting body 12 and the reflective frame 37 are cutsimultaneously, the light-emitting device 1000 of FIG. 22B is obtained.

FIG. 27A shows a cross-sectional view of an edge-lit backlight unit of aliquid crystal display in accordance with an embodiment of the presentdisclosure. The backlight unit includes a light source 901, a lightguide plate 902, and a diffusing plate 903. The light source 901includes a carrier 9011, a plurality of light-emitting devices 100disposed on the carrier 9011, and a circuit (not shown) formed on thecarrier to control the light-emitting devices 100. The light source 901is arranged at two side of the light guide plate 902. When thelight-emitting device 100 emits light, since light (R) emits outward inthe Z direction (to exit the light-emitting devices 100), the carrier9011 is arranged perpendicular to the light guide plate 902 (that is,the light-emitting surface of the light-emitting device 100 isperpendicular to the carrier 9011) which can effectively directs thelight (R) into the light guide plate 902. When the light (R) emits intothe light guide plate 902, the light guide plate 903 alters thedirection of the light (R) toward the diffusing plate 903. Optionally, areflector 904 can be disposed on the light guide plate 902 opposite tothe diffusing plate 903 for reflecting the light (R). The extensionelectrode layers 15A, 15B of the light-emitting device 100 are mountedon the circuit of the carrier 9011 through solder. In one embodiment,the carrier 9011 and the reflector can be integrally formed as one-pieceobject and in an L-shape form. In addition, the light-emitting devices100 are arranged on one side of the light guide plate 902 for reducingmaking cost and simplifying the assembly.

FIG. 27B shows a perspective view of a light source 902 and thelight-guiding plate 902 of FIG. 27A. The light-emitting devices 100 arearranged along the X direction to form one-dimensional array. The secondreflective layer 17 is parallel to the long side of the carrier 9011. Inthis embodiment, the number and arrangement of the light-emitting device100 is illustrative, and not intended to limit the scope of the presentdisclosure. Since the light-emitting device 100 has the light-emittingangle of 130˜150° in the long side direction (X direction), the distance(D5) between two adjacent light-emitting devices 100 ranges from 12 mmto 15 mm which does not cause dark area in the light guide plate 902.Based on different application, the distance (D5) can range from 4 mm to15 mm.

FIG. 28 shows a cross-sectional view of an edge-lit backlight unit of aliquid crystal display in accordance with an embodiment of the presentdisclosure. Similar to FIG. 27A, in FIG. 28, the light-emitting device600 replaces the light-emitting device 100. The light-emitting device600 only has a side with the second reflective layer 17. The side of thelight-emitting device 600 without the second reflective layer 17 facesthe reflector 904. Therefore, the light (R) from the light-emittingdevice can be reflected by the second reflective layer 17 toward thereflector 904, and further is redirect toward the diffusing plate 903through the reflector 903 for increasing the overall light intensity ofthe liquid crystal display.

FIG. 29 shows a cross-sectional view of an edge-lit backlight unit of aliquid crystal display in accordance with an embodiment of the presentdisclosure. The light source 901 includes a carrier 9011, a plurality oflight-emitting devices 700 disposed on the carrier 9011. Since light (R)emits outward in the Y direction (to exit the light-emitting devices700), the carrier 9011 is arranged parallel to the light guide plate 902(that is, the light-emitting surface of the light-emitting device 700 isparallel to the carrier 9011) which can effectively directs the light(R) into the light guide plate 902.

It will be apparent to those having ordinary skill in the art thatvarious modifications and variations can be made to the devices inaccordance with the present disclosure without departing from the scopeor spirit of the disclosure. In view of the foregoing, it is intendedthat the present disclosure covers modifications and variations of thisdisclosure provided they fall within the scope of the following claimsand their equivalents.

What is claimed is:
 1. A light-emitting device comprising: alight-emitting structure with a side surface; and a reflective layercovering the side surface; wherein the light-emitting device has a firstlight-emitting angle and a second light-emitting angle, and a differencebetween the first light-emitting angle and the second light-emittingangle is larger than 15°.
 2. The light-emitting device according toclaim 1, further comprising a light-transmitting body enclosing thelight-emitting structure.
 3. The light-emitting device according toclaim 2, wherein the light-transmitting body has a top surface and abottom surface opposite to the top surface, and the light-emittingdevice comprises a pair of extension electrode layers disposed on thebottom surface.
 4. The light-emitting device according to claim 2,wherein the light-transmitting body has a first side surface, a secondside surface, a third side surface and a fourth side surface, and thereflective layer covers the first side surface and the third sidesurface without covering the second side surface and the fourth sidesurface.
 5. The light-emitting device according to claim 4, where thefirst side surface is opposite to the third side surface and the secondside surface is opposite to the fourth side surface.
 6. Thelight-emitting device according to claim 1, wherein the firstlight-emitting angle is of 130˜150°.
 7. The light-emitting deviceaccording to claim 1, wherein the second light-emitting angle is of100˜125°.
 8. The light-emitting device according to claim 1, wherein thelight-emitting device has merely three light-emitting surfaces.
 9. Thelight-emitting device according to claim 1, further comprising anextension electrode layer overlapping the reflective layer.
 10. Thelight-emitting device according to claim 1, further comprising anextension electrode layer having a side surface coplanar with thereflective layer.
 11. The light-emitting device according to claim 3,wherein the reflective layer has an inner surface with a first portioninclined with respect to the top surface and a second portionsubstantially perpendicular to the top surface.
 12. The light-emittingdevice according to claim 11, wherein the first portion has a heightlarger than that of the light-emitting structure.